It will include all the routes from that router as part of it.

/// note | Technical Details

It will actually internally create a *path operation* for each *path operation* that was declared in the `APIRouter`.

So, behind the scenes, it will actually work as if everything was the same single app.

///

/// check

You don't have to worry about performance when including routers.

/// tip | Tipp

Mehr dazu finden Sie in der Dokumentation zu [Hinter einem Proxy – Proxy-Forwarded-Header aktivieren](../advanced/behind-a-proxy.md#enable-proxy-forwarded-headers){.internal-link target=_blank}

///

## Zusammenfassung { #recap }

相対URLを使っているので、APIが`https://example.com/`にある場合、`https://example.com/token`を参照します。しかし、APIが`https://example.com/api/v1/`にある場合は`https://example.com/api/v1/token`を参照することになります。

相対 URL を使うことは、[プロキシと接続](../../advanced/behind-a-proxy.md){.internal-link target=_blank}のような高度なユースケースでもアプリケーションを動作させ続けるために重要です。

///

                    is used for substitution in the server's URL template.

                Read more in the
                [FastAPI docs for Behind a Proxy](https://fastapi.tiangolo.com/advanced/behind-a-proxy/#additional-servers).

                **Example**

                ```python
                from fastapi import FastAPI

                app = FastAPI(

func newContext(r *http.Request, w http.ResponseWriter, api string) context.Context {
	reqID := w.Header().Get(xhttp.AmzRequestID)

	vars := mux.Vars(r)
	bucket := vars["bucket"]
	object := likelyUnescapeGeneric(vars["object"], url.PathUnescape)
	reqInfo := &logger.ReqInfo{
		DeploymentID: globalDeploymentID(),
		RequestID:    reqID,
		RemoteHost:   handlers.GetSourceIP(r),
		Host:         getHostName(r),

* `fastapi-people.md`
* `external-links.md`
* `newsletter.md`
* `management-tasks.md`
* `management.md`
* `contributing.md`

Some of these files are updated very frequently and a translation would always be behind, or they include the main content from English source files, etc.

#### Request a New Language

   * {@link #toString} on the {@link #entrySet}, yielding a result such as {@code [a x 3, c, d x 2,
   * e]}.
   */
  @Override
  String toString();

  // Refined Collection Methods

  /**
   * {@inheritDoc}
   *
   * <p>Elements that occur multiple times in the multiset will appear multiple times in this
   * iterator, though not necessarily sequentially.
   */

   * {@link #toString} on the {@link #entrySet}, yielding a result such as {@code [a x 3, c, d x 2,
   * e]}.
   */
  @Override
  String toString();

  // Refined Collection Methods

  /**
   * {@inheritDoc}
   *
   * <p>Elements that occur multiple times in the multiset will appear multiple times in this
   * iterator, though not necessarily sequentially.
   */

   *     intersection
   * @since 27.0
   */
  public Range<C> gap(Range<C> otherRange) {
    /*
     * For an explanation of the basic principle behind this check, see
     * https://stackoverflow.com/a/35754308/28465
     *
     * In that explanation's notation, our `overlap` check would be `x1 < y2 && y1 < x2`. We've

* Each application that you have running on your computer has some process behind it, each running program, each window, etc. And there are normally many processes running **at the same time** while a computer is on.
* There can be **multiple processes** of the **same program** running at the same time.